Air moving across an array of photovoltaic (PV) assemblies mounted to the roof of a building, or other support surface, creates wind uplift forces on the PV assemblies. Much work has been done in the design and evaluation of arrays of PV assemblies to minimize wind uplift forces. See U.S. Pat. Nos. 5,316,592; 5,505,788; 5,746,839; 6,061,978; and 6,148,570. Reducing wind uplift forces provides several advantages. First, it reduces the necessary weight per unit area of the array. This reduces or eliminates the need for strengthening the support surface to support the weight of the array, thus making retrofit easier and reducing the cost for both retrofit and new construction. Second, it reduces or eliminates the need for the use of roof membrane- (or other support surface-) penetrating fasteners; this helps to maintain the integrity of the membrane. Third, the cost of transporting and installing the assembly is reduced because of its decreased weight. Fourth, lightweight PV assemblies are easier to install than assemblies that rely on ballast weight to counteract wind uplift forces. Fifth, when designed properly, the assembly can serve as a protective layer over the roof membrane or support surface, shielding from temperature extremes and ultraviolet radiation.
A first aspect of the invention is directed to a multiple position photovoltaic (PV) assembly, for use on a support surface, comprising a base, a PV module having first and second PV module ends and a deflector having first and second deflector ends. The assembly also comprises means for placing the PV module and deflector at shipping and inclined-use states with the PV module placeable at shipping and inclined-use angles relative to the base, and the deflector placeable at deflector shipping and deflector inclined-use angles relative to the base. The second PV module and deflector ends define a gap therebetween when the PV module and deflector are at their respective inclined-use angles. The assembly may comprise a side deflector extending generally between the base, an edge of the PV module and an edge of the deflector when the PV module and deflector are in the inclined-use state.
A second aspect of the invention is directed to a multiple position photovoltaic (PV) assembly, for use on a support surface, comprising a base, a PV module having first and second PV module ends and a deflector having first and second deflector ends. A living hinge secures the PV module to the base so that the PV module is placeable at shipping and inclined-use angles relative to the base. A coupler movably connects the second PV module end to the second deflector end so that the deflector may move relative to the PV module between deflector shipping and deflector inclined-use angles relative to the base. A deflector connector secures the deflector to the base thereby placing the PV module and deflector in an inclined-use state with the PV module at said inclined-use angle and the deflector at said deflector inclined-use angle. The second PV module and second deflector ends define a gap therebetween when at their inclined-use angles.
A third aspect of the invention is directed to a multiple position photovoltaic (PV) assembly, for use on a support surface, comprising a base, a PV module having first and second PV module ends and a deflector having first and second deflector ends. The assembly also comprises a support structure supporting (a) the PV module at shipping and inclined-use angles relative to the base, and (b) the deflector at deflector shipping and deflector inclined-use angles relative to the base. The support structure comprises a living hinge, securing the first PV module end to the base so that the PV module is placeable at said shipping and inclined-use angles, and a deflector connector, securing the first deflector end to the base so that the deflector may move between said deflector shipping and deflector inclined-use angles relative to the base.
A fourth aspect of the invention is directed to a PV assembly comprising a base, a PV module having first and second PV module ends and a deflector having first and second deflector ends. The PV module and the deflector are mounted to the base with: the PV module at an inclined-use angle relative to the base, the inclined-use angle being an acute angle with the PV module extending away from the base and towards the deflector, and the deflector at a deflector inclined-use angle relative to the base, the deflector inclined-use angle being an acute angle with the deflector extending away from the base and towards the PV module. The deflector comprises an outer surface having a solar reflectivity of at least about 0.2, and preferably of at least about 0.7, whereby solar radiation contacting the outer surface may be redirected to an adjacent PV module to increase the power output of the adjacent PV module.
A fifth aspect of the invention is directed to a PV assembly comprising a base having a base width and a base length L, a PV module having a module width and first and second PV module ends defining a module length H therebetween, and a deflector having first and second deflector ends. The PV module and the deflector are mounted to the base with: the PV module at an inclined-use angle relative to the base, the inclined-use angle being an acute angle with the PV module extending away from the base and towards the deflector, and the deflector at a deflector inclined-use angle relative to the base, the deflector inclined-use angle being an acute angle with the deflector extending away from the base and towards the PV module. The inclined-use angle of the PV module is about 2xc2x0 to 15xc2x0. A ground cover ratio of H/L is about 0.6 to about 0.8.
A sixth aspect of the invention is directed to a PV assembly comprising a base and a PV module mounted to the base to overlie the base. The base comprises a foam body having an upper surface, a lower surface and a peripheral edge, a first moisture barrier at the upper surface, and a second moisture barrier at the lower surface. The foam body may comprise a closed-cell foam. At least one of the first and second moisture barriers may comprise means for mitigating the degradation of the thermal insulation properties of the foam body due to diffusion of moisture into the foam body. The first moisture barrier may comprise an impermeable cover and the second moisture barrier may comprise a skin formed on the lower surface of the foam body.
Various features and advantages of the invention will appear from the following description in which the preferred embodiments have been set forth in detail in conjunction with the accompanying drawings.